(1) Field of the Invention
This invention relates to an active pixel sensor fabricated using standard CMOS processing and more particularly to dark current suppression and improved sensitivity in active pixel sensors fabricated using standard CMOS processing.
(2) Description of the Related Art
U.S. Pat. No. 6,649,950 B2 to He et al. describes substantially covering the surface of a photodiode structure in order to reduce dark current due to surface damage to the photodiode structure.
U.S. Pat. No. 6,621,064 B2 to Chen et al. describes a device utilizing a buried junction away from the surface to reduce dark current.
U.S. Patent Application Publication No. US 2004/0046104 A1 by Rhodes describes a CMOS imager in which the floating diffusion is connected to a gate of a source follower transistor by a doped polysilicon contact to provide a better ohmic contact and reduce leakage into the substrate.